LOS CABOS, Mexico, June 18 (Reuters) - World leaderspressured Europe on Monday to take ambitious new steps toresolve its debt crisis after a victory for pro-bailout partiesin a Greek election failed to calm markets or ease worries thatwider turmoil could derail the global economy.

The world's major industrialized and developing economieswere set to urge Europe to take "all necessary policy measures"to resolve a crisis that has now raged for over two years,according to a draft communique seen by Reuters that wasprepared for a Group of 20 summit in this Mexican resort town.

U.S. President Barack Obama, concerned Europe's woes couldupend his re-election hopes, requested a meeting with itsleaders on Monday evening.

Earlier he met with Germany's Angela Merkel, who as theleader of Europe's biggest economy is under intense pressure toexplore bold new short-term measures, but has so far resisted.Obama's spokesman said the U.S. president was encouraged by thetalks, which touched on steps to "increase Europeanintegration".

European officials rejected the notion that they were toblame for weakening growth across the globe, and played downhopes for any quick miracle cure for the 17-nation euro zone.

"Frankly, we are not coming here to receive lessons in termsof democracy or in terms of how to run our economy," saidEuropean Commission President Jose Manuel Barroso.

Protected by Mexican navy vessels and troops on sun-bakedbeaches and highways, leaders from the Group of 20 countriesrepresenting more than 80 percent of world output began atwo-day meeting to prioritize growth and job creation against abackdrop of a weakening global economy.

Rising violence in Syria and the near-collapse of a UnitedNations-brokered peace plan was also in focus as U.S. PresidentBarack Obama met with Russian President Vladimir Putin. The twosuper powers have clashed over arming Syria and U.N. sanctions.

Obama and Putin agreed that the violence in Syria has to endbut offered no new solutions and showed no signs of reaching adeal on tougher sanctions against Damascus.

But Europe's battle against a debt crisis that has ledGreece, Ireland and Portugal to seek EU/IMF rescues, and forcedSpain to seek aid for its banks, was set to dominate an openingdiscussion of G20 leaders on the global economy.

The World Bank lowered its forecast for global growth in2012 to 2.5 percent and warned that developing countries faced along period of financial market volatility and weaker growth.

RELIEF RALLY FLEETING

A narrow victory for the conservative New Democracy party inthe Greek election on Sunday eased concerns the heavily indebtedcountry could exit the euro zone soon but did little to calmfinancial markets.

After an initial relief rally, the euro fell against thedollar and Spanish bond yields hit a new euro-era high above 7percent. European stocks ended 1.2 percent lower.

Fitch Ratings agency said the Greek result had lowered therisk of a disorderly default and the scenario of a euro zoneexit, but it also warned that any new government in Athens waslikely to be fragile.

"The win in Greece does not really resolve anything," saidBoris Schlossberg, managing director at investment advisory firmBK Asset Management in New York. "It's still going to be toughfor Greece."

Merkel, speaking to reporters after landing on the southerntip of Mexico's Baja California peninsula in the middle of thenight, welcomed the Greek result but said she could not acceptany loosening of the austerity measures and deep structuralreforms Athens has agreed to as a condition of its two EU/IMFbailouts totaling 240 billion euros.

"The Greek government will and must deliver on thecommitments it has agreed to," she said.

That puts her on a collision course with the winner of theGreek vote, conservative Antonis Samaras, who campaignedpledging to renegotiate elements of the rescue and reiteratedthat stance on Monday, saying "amendments" were needed torelieve "crippling unemployment and huge hardships" for Greeks.

Greece will ask to spread 11.7 billion euros in austeritycuts over four years instead of two, a New Democracy partysource told Reuters in Athens.

German frustration with Greece's failure to deliver on itsreform pledges has risen in recent months, as has Greek anger atthe tough austerity prescribed by Berlin and its partners.

In a twist of fate, Greece's soccer team will battle Germanylater this week in the quarter-finals of the Europeanchampionships.